OMEF · Tree shear

OMEF Big Inch BI300

Name: OMEF Big Inch BI300
Brand: OMEF

420 kg shear for 8-14 t excavators, 300 mm published maximum cut — the regrowth and fence-line workhorse.

4 published specificationsAustralian representation: Randalls

Positioning

Where this machine sits

The BI300 is the small end of the Big Inch range — 420 kg on 8-14 tonne excavators with a 300 mm published maximum cut. That combination describes the regrowth and fence-line workhorse: a shear light enough that a common small excavator can hold it at reach, on material that does not need a large attachment.

The commercial logic of a shear at this size is access and utilisation rather than capacity. A 10 tonne excavator with a shear reaches sites a larger machine cannot, and returns to earthmoving, drainage and general work when clearing is not running.

Published figures

Specifications

Indicative published manufacturer and distributor information. Confirm every figure, lift chart and hydraulic requirement with the manufacturer or authorised dealer before purchase.

Carrier class	8-14 t
Weight	420 kg
Maximum published cut	300 mm
Australian distributor	Randalls

Interpretation

What the published figures actually constrain

A specification table tells you what the machine is. This is what each of those numbers means for the work you would put it to.

Published figure	What it means commercially
8-14 t carrier class, 420 kg attachment	Light enough that carriers in this class can hold it at reach. Still verify the lift chart with the attachment fitted — small carriers have correspondingly small charts.
300 mm published maximum cut	What the shear can sever, not what the carrier can hold. Green hardwood at 300 mm is heavier than most buyers estimate, and the boom is usually the limit before the blade is.
Randalls Australian distribution	Local distribution for parts, blades and service. Confirm what is held in Australia, because blade and pivot wear are ongoing rather than occasional.
Shear rather than saw	Fast, simple and mechanically straightforward, with a crushed rather than clean cut. Where material can fall freely and cut quality does not matter, that is the right trade.

Before it fits

The four checks that decide whether your carrier can run this

Each of these can fail independently, and passing one says nothing about the others. Weight class alone is the weakest of the four and the one most often relied on.

Check	For this attachment
Mass the carrier must control at reach	420 kg plus rotator and coupler, on an 8-14 t excavator. Small carriers have correspondingly small charts — run it.
Continuous hydraulic flow	Confirm the auxiliary circuit meets the shear's requirement; on smaller excavators this is worth verifying rather than assuming.
Working pressure	Verify pressure at the flow the shear actually draws during a cut.
What usually binds first	Not the hydraulics. Green hardwood at 300 mm is heavier than most operators estimate, and the boom typically runs out before the blade does.

Commercial fit

Where this machine earns its cost

Right machine when

Regrowth control, fence lines, shelterbelts and fire-break work in the 100-200 mm class
Contractors with an existing 8-14 t excavator that needs to earn across several industries
Work where stems per minute matters more than occasional large capacity

Wrong machine when

The stand is dominated by stems near or above 300 mm — production collapses at the top of the range
Plantation clearfell, where a feller buncher is the correct machine

Before you sign

Verify these for this specific model

Beyond the standard buying criteria for the class, these are the questions this machine in particular raises.

Stems per minute in your dominant diameter, witnessed on site
Behaviour in stringy eucalyptus, which is the real Australian test
Whether multiple stems can be accumulated before placing
Lift chart with 420 kg fitted at full reach

Running cost

What drives the cost of owning this machine

The attachment's cost is small relative to the carrier's, so the economics are really the carrier's economics. A small excavator earning across clearing, civil and drainage work carries its fixed cost across far more hours than a dedicated machine.

Blade and pivot wear are the recurring costs, and they scale with material hardness and with cutting close to the ground where grit is picked up.

Where cut quality matters — near assets, or where the stump face affects what follows — a shear is the wrong tool regardless of its economics. The comparison with grapple saws and tree shears sets out where each belongs.

In practice

Ownership considerations in Australian conditions

Check the lift chart, not just the cut rating

A 300 mm rating describes severing capacity. Whether the carrier can hold a 300 mm green hardwood stem at reach is a separate and more decisive calculation.

Confirm the auxiliary circuit

Flow and pressure requirements must be met by the carrier's auxiliary hydraulics. On smaller excavators this is worth verifying rather than assuming.

Match the tool to the finish required

A shear crushes rather than cuts cleanly. Where the cut face matters — for regrowth control, disease management or appearance — that is a reason to use a different attachment.

Questions

Common questions about this machine

Is the 300 mm rating the practical working limit?

The blade's limit, yes; the job's limit is usually the carrier. Green hardwood at 300 mm is heavy, and an 8-14 tonne excavator's lift chart at reach frequently runs out before the shear does. Run the chart with the attachment, rotator and coupler weight deducted at the reach the work actually uses — that is the number that decides what you can safely handle.

Shear or grapple saw for this size of carrier?

Shear where material can fall freely and cut quality does not matter — it is faster, simpler and cheaper. Grapple saw where the piece must be held through the cut and placed deliberately, which is the case near buildings, services and traffic. The two are not competing on the same work, and many fleets carry both.

Does the crushed cut face matter?

It depends what follows. For clearing where material is removed and the stump is treated or ignored, it rarely matters. Where regrowth control, disease management or appearance are part of the specification, a crushed face is a genuine disadvantage and a saw-based attachment is the right tool.

Same class

Alternatives to compare against

Other tree shears covered in this guide.

OMEF

Big Inch BI500

1,810 kg shear for 23-30 t excavators with 600 mm published maximum cut.

OMEF

Big Inch BI600

2,400 kg shear for 30 t+ carriers needing ~250-300 L/min — a different category from compact shears.

TMK

TMK 300

310 kg shear for 6-20 t excavators — 250 mm hardwood, 300 mm softwood, and the difference matters.

In service

Fleet packages that use this class

Package D

Commercial land clearing

A deliberately flexible attachment-based system. Instead of owning six specialised purpose-built forestry machines, the same base excavator generates revenue across civil earthworks, demolition, vegetation clearing, log handling, tree removal, stump removal, road construction and drainage.